i have a 1985 2+2. i took it to the test only smog center and it failed.

hc was allowed 128 at 15mph i got 202
at 25mph it was allowed 103 i got 154

co% was allowed .80 at 15mph and i got .65
but at 25 i was allowed .60 and i got .64

no(ppm) was allowed 1106 at 15 and i got 1352
at 25 i was allowed 936 and i got 2722

anyone know what would cause my car to failed so bad? any sensors i should check?

 

Turning down the timing helps. It didn't fail by much, so turn down the timing, check (and replace if needed) the spark plugs & O2 sensor.

Also, when I doubt a car is going to pass emissions, I show up to a shop in my mechanic outfit & ask if they can quickly put my car on the emissions machine on test mode to see what it puts out. If they aren't busy, they usually will.

 

How old is your catalytic converter? If it's over five yrs old, change it. Then, put the old one back after it passes. Put the new one away for two yrs and switch it for the testing. Converter is bolt on. Check the wire harness to the O2 sensor. Also, put new PCV valve, they are cheap. New O2 sensor; about 27 dollars at Kragen. Buy "Guaranteed to Pass" additive at Kragen and use as directed. Put timing at manufacturer's spec. You will pass.
Rey